> Markdown version of [/jobs/ext/2159785-senior-fullstack-software-engineer-ecosystem-experience](https://www.wearedevelopers.com/jobs/ext/2159785-senior-fullstack-software-engineer-ecosystem-experience). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Fullstack Software Engineer - Ecosystem Experience - **Company:** Semble - **Location:** London, UK (Remote available) - **Experience:** Expert - **Salary:** £70,000.0 - £90,000.0 - **Contract:** Permanent contract - **Skills:** Application Programming Interfaces (APIs), Amazon Web Services, Automation of Tests, Software as a Service, Cloud Computing, Code Review, Continuous Integration, Software Debugging, Automation of Marketing, MongoDB, Node.Js, NoSQL, Operational Data Store, TypeScript, Web Applications, Openapi, Datadog, Data Logging, File Transfer Protocol (FTP), Apache Yarn, ReactJS, Fast Healthcare Interoperability Resources, Cypress (Programming Language), Zapier, Backend, Material UI, Playwright, Health Level Seven International, Graphql, Front End Software Development, Terraform, Webhooks - **Published:** August 21, 2026 - **Apply:** https://www.adzuna.co.uk/jobs/details/5849699297 ## About the Role As a senior engineer on Ecosystem Experience, you'll own problems end to end - from partner discovery through design, implementation, rollout, and production reliability., We're looking for a senior fullstack engineer who enjoys messy real-world integrations as much as clean product UI - someone comfortable reading a partner OpenAPI spec in the morning and shipping a resilient production path by the afternoon. You should already be operating at a senior level: driving work independently, elevating those around you, and thinking beyond the ticket in front of you. Must-Haves * 5+ years' professional experience building production web applications with React and TypeScript, including substantial time operating as a senior / staff-of-one on complex features. * Strong hands-on experience with Node.js backends and APIs (REST and/or GraphQL). * Proven experience integrating with third-party systems - APIs, webhooks, auth flows, retries, idempotency, credentials/secrets. * Ability to design systems, not just implement tickets: break down large problems, define interfaces/contracts, and leave codebases easier to change than you found them. * Comfort working in ambiguity - clarifying requirements, challenging weak specs, and driving decisions when information is incomplete. * A production ownership mindset: debugging complex issues across services, reading logs/metrics traces, and preventing the same incident twice. * Solid automated testing habits (unit/integration/e2e) and comfort with CI/CD; you know when to add coverage and when not to over-engineer. * Experience with NoSQL databases (MongoDB or similar) and cloud-hosted applications (AWS preferred). * Strong written and verbal communication - RFCs/tech notes, partner discussions, and clear updates for Product and other engineers. * Collaborative leadership without needing formal authority: mentoring, reviewing thoughtfully, and aligning people around a plan. * Security and privacy awareness appropriate for handling sensitive healthcare data - least privilege, secrets hygiene, safe logging. * Comfort using AI coding tools to accelerate delivery without lowering the quality bar. Strong Pluses * Healthcare, HL7/FHIR, lab/pharmacy, or other regulated-domain integrations. * iPaaS / automation platforms (Workato or similar). * Design systems / component libraries, and large monorepo experience. * Infrastructure as Code (Terraform / CDK), observability (Datadog or similar), and multi-tenant SaaS. * Experience leading technical delivery across multiple engineers or workstreams. * Playwright or Cypress e2e experience. * Bilingual English-French. ## Description * Lead the design and delivery of integrations that move clinical and operational data safely between Semble and external systems, including REST/GraphQL APIs, webhooks, HL7, SFTP, and iPaaS/automation flows. * Work across the stack in our Yarn/Nx TypeScript monorepo: React on the frontend, Node.js services and domain modules on the backend, GraphQL (internal and public APIs), and MongoDB. * Take ambiguous partner specs and product goals and turn them into clear technical designs, sequenced delivery plans, and clinically safe, testable solutions. * Make sound architectural trade-offs - simplicity vs flexibility, build vs buy, speed vs long-term maintainability - and document the decisions so others can follow them. * Own production outcomes: monitoring and alerting (e.g. Datadog), incident diagnosis, root-cause analysis, and durable fixes - not just shipping features. * Improve reliability and operability: failure handling, retries, idempotency, credentials/secrets, multi-tenant config, and safe rollouts across many production environments. * Contribute to Semble Connect and related automation - provisioning, connections, recipe/webhook patterns, and the product surfaces that expose them to practices. * Set a high quality bar through design reviews, thorough code reviews, automated tests (unit, integration, e2e), and pragmatic CI/CD improvements. * Mentor and unstick teammates; give clear feedback; help more junior engineers grow without becoming a bottleneck. * Influence the Ecosystem Experience roadmap and technical standards - surfacing risks early, proposing better approaches, and aligning stakeholders when requirements conflict. ## Related Videos - [Putting the Graph In GraphQL With The Neo4j GraphQL Library](https://www.wearedevelopers.com/videos/257-putting-the-graph-in-graphql-with-the-neo4j-graphql-library) - [HR ROBO SAPIENS: Decoding AI Agents and Workflow Automation for Modern Recruitment](https://www.wearedevelopers.com/videos/1470-hr-robo-sapiens-decoding-ai-agents-and-workflow-automation-for-modern-recruitment) - [Leveraging Real time data in FSIs](https://www.wearedevelopers.com/videos/806-leveraging-real-time-data-in-fsis) - [Navigating the Corporate Jungle: Life as a Developer in a large Company](https://www.wearedevelopers.com/videos/621-navigating-the-corporate-jungle-life-as-a-developer-in-a-large-company) - [GraphQL + Apollo + Next.js: A Lovely Trio](https://www.wearedevelopers.com/videos/311-graphql-apollo-next-js-a-lovely-trio) - [Create a Programmatic SEO Project Using Next.js and Static Site Generation](https://www.wearedevelopers.com/videos/449-create-a-programmatic-seo-project-using-next-js-and-static-site-generation) ## Related Articles - [Fully Remote Software Engineer Jobs](https://www.wearedevelopers.com/magazine/447-fully-remote-software-engineer-jobs) - [Find a Developer Job: 12 Best Job Sites For Developers](https://www.wearedevelopers.com/magazine/165-find-a-developer-job-12-best-job-sites-for-developers) - [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated) - [Fullstack Developer Salary UK](https://www.wearedevelopers.com/magazine/251-fullstack-developer-salary-uk) - [How We Built a Worry-Free System That Runs for 10+ Years – And What We’d Do Again](https://www.wearedevelopers.com/magazine/751-how-we-built-a-worry-free-system-that-runs-for-10-years-and-what-we-d-do-again) - [Where To Find Software Engineering Jobs](https://www.wearedevelopers.com/magazine/396-where-to-find-software-engineering-jobs)